Autoclave



Jan. 21, 1964 B. c. voN PLATEN 3,118,177.

AUTocLAvE Filed June 20, 1960 3 Sheets-Sheet 1 B. C. VON PLATEN Jan. 21, 1964 AUTOCLAVE Filed June 20, 1960 Jan. 21, 1964 B. cfvoN PLATEN AUTOCLAVE 5 Sheets-Sheet 5 Filed June 20, 1960 United States Patent O Il 3,118,177 AUTQCLAVE Baltzar Carl von Eaten, Stockholm, Sweden, assigner to Allinnna Svenska lllektrisira Alrtiebolaget, Vasteras,

Sweden, a Swedish corporation Filed .lune 29, E69, Ser. No. 37,271 lil Qlaims. (iii. 18-5) For carrying out certain chemical processes it is necessary to bring about an extremely high pressure in the space where the chemical reaction shall tal-:e place.

Autoclaves are known which comprise an inner chamber bounded by a container and by a piston movable in an opening in the container. The pressure in the chamber is brought about with the aid of a fluid arranged outside the container and its piston, which are in turn surrounded by the walls of an outer vessel. Such an autoclave has the great disadvantage that the pressure distribution in the inner chamber is very uneven, especially when the substances subjected to pressure are solid. Further, risks exist that internal stresses in the walls of the container will result in rupture at too low stresses.

Further, high pressure presses are known which comprise four anvils each with a pressure surface in the form of an equilateral triangle and movable along axes perpendicular to the pressure surfaces. The anvils converge to a common intersection and the pressure surfaces thereby form a regular tetrahedron. The material which is to be subjected to pressure, is enclosed in a pressure transmitting and sealing carrier substance which is shaped to a regular tetrahedron with greater dimensions than those of the regular tetrahedron defined by the pressure surfaces of the anvils. The edge of the carrier substance tetrahedron can be percent greater than the edge of the tetrahedron which the pressure surfaces of the anvils form, when the pressure surfaces are brought to lie edge to edge. Each of the anvils is provided with a separate hydraulic press to move it. The presses bring the anvils to press the carrier substance tetrahedron together, whereby a high pressure is generated therein. In an arrangement of the described type, great diiiculties exist in obtaining a uniform and equally high pressure everywhere in the high pressure room because of every anvil having its separate press. in order that uniformity in movement of the anvils and presses shall be attained the presses are provided with complicated guiding means taking up much space.

According to the present invention variations in pressure in a high pressure chamber are avoided without complicated means for that purpose taking up much space being required. Further, risks are eliminated that internal tangential stresses in the walls of a homogenous container will give rise to rupture in the walls.

The invention relates to an autoclave for treatment of material at high pressures, comprising an outer chamber containing a pressure medium, an inner chamber situated within the outer chamber and a movable pressure transmitting mechanical means situated between the rooms. rl`he autoclave is characterised in that the mechanical means comprises a plurality of separate blocks which have cross section surfaces decreasing in direction from the outer to the inner chamber and which are separated from each other by interstices, gaps or slots running in direction between the rooms. The interstices, gaps or slots are sealed from the inner chamber, the high pressure chamber. The seal is suitably brought about by separate sealing means. The interstices can be in communication with a space with lower pressure than that in the high pressure chamber, e.g., with the outer atmosphere. Because that side of each block which is exposed to the outer chamber is larger than that side exposed to the inner chamber, the pressure transmitting organ has a pressure multiplying eiect.

ICC

The autoclave can, for example, be shaped so that the locks outwardly form a sphere. The pressure medium in the outer chamber may, eg., consist of a fluid under high pressure. The pressure in the high pressure chamber is brought about by the blocks under the influence of the pressure medium in the outer chamber being displaced inwards so that the material enclosed in the high pressure chamber is compressed.

Because the pressure transmitting means situated between the outer and the inner chamber comprises several separate blocks, the result is obtained that the stresses in the means are distributed in a very favourable manner so that forces directed in the movement direction of the blocks do not give rise to forces with components perpendicular thereto. Such forces will arise in the walls of a continuous container with a piston movable in an opening, and they will result in rupture of the walls of the container at a lower pressure than that which the means in the autoclave according to the invention withstands.

rhe invention will be explained in more detail by way of examples with reference to the attached drawing, in which:

FlGURE l shows a section through an autoclave, where six pressure transmitting blocks form inwardly a cubic high pressure chamber and outwardly a sphere which is surrounded by two semi-spherical caps of thin plate and is enclosed in a chamber filled with a fluid with adjustable, high pressure.

FEGURE 2 shows a section in part through the same autoclave as in FIGURE l in a plane forming an angle of 45 to the section in FGURE l.

FIGURE 3 shows in perspective a block of the same form as those being integral parts of the autoclave according to FGURES l and 2, but modied.

IGURE 4 shows in perspective a block for an autoclave with a high pressure chamber in the form or a regular tetrahedron.

FGURE 5 shows a side section through an autoclave in which the blocks form a cylinder enclosed in a liquid filled container.

FIGURE 6 shows a cross section through the plane A-A of the autoclave according to FIGURE 5.

In FIGURES l and 2 the numeral 2l indicates a hydrostatic pressure cylinder which is closed at both its ends by the cylindrical covers 22 and 23 so that a closed container is formed. This container is inserted in a stand which is not shown in the drawing and which will take up the axially directed forces acting on the plates 22 and 23 at an over-pressure. The radially acting forces are absorbed by the walls of the cylinder 2i.

inside the pressure cylinder there is a cubical room 24 which is surrounded by six pyramid shaped blocks which have :dat square top surfaces and spherical bottom surfaces. The blocks are separated by interstices, gaps or slots 25. The blocks can be divided into two parts along a spherical parting surface concentric with their bottom surface. Five of the blocks are alike and consist of au outer part 26 and an inner part 27 which parts are held together by bolts 2S. The sixth block consists of an outer part 29 and an inner part 3i) which parts are held together by tie bolt 31 provided with a ilange 32 and the washer 33. This bolt is surrounded by a tube 34 of an electrically insulating material, and is used for the delivery of electrical current to produce a chemical reaction in the chamber 24. In the room the material to be subjected to a pressure is placed. The material may, c g., be embedded in a pressure transmitting substance such as pyrophyllite, talcum, indium, bismuth, silver chloride and boron nitride. Some of the mentioned pressure transmitting substances can thereby themselves serve for sealing against the interstices 25. Separate sealing means can rf--f also be used, e.g., strips of a tool steel such as C 550 (Fagersta Bruh AB, Sweden) or SAE/AISI A2 with a hardness of RC 55-65. The material to be treated may also be placed in a cubical container which is suitably reinforced at the edges with sealing strips of the mentioned type.

The blocks are held together by washers 36 which engage in the grooves 37 and which are threaded on the bolts 3S and the cap shaped washers 39. The block which consists of parts 29 and 343 rests on a support d@ which is attached to the part 25@ by the bolts 4l. This support nl rests against the plate 23.

Shields 64 and strips 42 cover the interstices 25. The shields 6d are at the place where three interstices meet. The space between a shield 64;. and the three strips l2 is covered by a washer 65. Two mainly semi-spherical caps of metal i3 and i4 are joined with each other and enclose the spherical body formed by the blocks. These caps separate the interstices 25 fluid-tightly from the liquid iilled chamber 45. Two sealing means 46 and i7 of e.g. rubber, which are tightly joined to each other prevent iluid finding its way out from the chamber 45. The cap 44 and the sealing means 46 are also tightly joined with the support 4t). At the corner between the cylinder 2i and the plates 22 and ZES there are inserted elastic support rings 67 of steel and rings 66 of elastic material, eg. rubber. The pressure medium, e.g. a hydraulic liuid is delivered to the chamber 45 from a pressure source not shown by the valve 48, the channel 49 and the nozzle Si? in the plate 23.

The interstices 25 are entirely separated from the chamber 24 as well as the chamber 45, but are in communication with a cooling medium source through the pipe lines 51 and 52 in the slot 53 in the plate Z3, the channels 54 and 55 (see FIGURE 2) in the socket 56, the channels 57 and 58 in the support 4t?, the channels 59 and Si) in the part 29 and the tubes 61 and 62 which are connected to the channels 59 and 6l) and project into the interstices 25. The pipes 6l and 62 are directed towards the room 24. The numeral 63 indicates an electric conductor which is connected to the bolt 3l. Through the conductor 63 electrical current can be conducted to the reaction chamber 24. In this chamber elements for electrical heating can be built in, eg. rods, spirals or helixwound threads, tubes or plates of suitable resistance material. The current can be conducted away from the chamber 24 through its walls and further to the outside of the apparatus where suitable contacts may be arranged.

The caps 43 and 44 will be deformed when the pressure is applied in the chamber 45 and they will be forced against the metallic parts which they enclose, i.e. the strips 42 and shields 64, the spherical surfaces of the parts 29 and the support dii. Due to the existence of the interstices 2S and the low pressure in them, the pyramidical parts are moved towards the centre of the sphere thereby exerting a pressure on the material enclosed in the chamber 24.

In the blocks the parts 27 and Sil may be made, c g. of the tool steel WKE Brilliant (Fagersta Brulr AB, Sweden) or SAE/AISI T4 with a hardness of RC 65-67 or of a hard metal, eg. Coroniant H5 (Sandvilren lernverks AB, Sweden) or Carboloy 999 (General Electric (2o.). The parts 26 and 29 may be of e.g. the tool steel D 249 (Fagersta Bruk AB, Sweden) or SAE/AISI S1 with a hardness of RC -60. The caps i3 and 44 may be constructed of metal, e.g. copper, of a plastic, or rubber, or similar materials. The form of a block of the autoclave according to FGURES l and 2 will be clear from FIG- URE 3. The block is substantially a truncated spherical sector. It has a substantially plane and quadratic surface 7i?, forming a wall in the cubical chamber 24, and four substantially plane surfaces 71, each of which lies in a plane running substantially through a side '72 of the square and through the centre of the cubical chamber 24.

Further, the block has a substantially spherical calotte not visible in FIGURE 3. Y

The surface 7b is substantial-ly perpendicular to the symmetry line of the block. The block according to FIGURE 3 is composed of three concentrically arranged parts of different materials. The part 73 may be eg. of the same material as the part 27 of the block according to FUURE l, the part 75 of the same materiales the part 25 and the part '74, e.g. of the tool steel C 55() (Fagersta lruk AB, Sweden) or SAE/AlSl A2 with a hardness of RC 55-60.

The block according to FIGURE 3 may also be shaped as a truncated pyramid. The side of the block not shown in the figure is then a substantially plane surface parallel to the surface 79.

The block according to FIGURE 4 has a substantially plane surface 76 consisting of an equilateral triangle. Four such blocks can be put together to form a regular polyhedron in the saine way as the six blocks in accordance with FIGURES l-3. With four blocks according to FIGURE 4, a cuical pressure Chamber' will not be formed as earlier, but instead, a pressure chamber in the forni of a regular tetrahedron. Each of the substantially plane sides 77 of the blocks lies in a plane running substantially through one side 7S of the triangle and through the centre of the tetrahedron formed by the four blocks. The surface '76 is substantially perpendicular to the symmetry line of the block. The block has a substantially spherical calotte, not visible in FIGURE 4, but it may also, as is the case with the block according to FIG- URE 3, have the form oi a truncated pyramid.

By combining blocks consistinn of truncated pyramids, of course, outwardly not a sphere but a polyhedron, square or tetrahedron respectively, is formed. This includes selfevident modiiications of certain means in FIGURES l and 2, T he caps d3 and ix/l e.g. are not given spherical form but are brought to agree with the form of the polyhedron.

The room 24 can have not only the form of a tetrahedron and a cube. Thus it can be an octahedron, dodecahedron, etc. Each block thereby gives a surface in the polyhedron. The surfaces of the blocks forming the interstices, gaps or slots lie in planes running through the centre of the polyhedron and through one side of the polygon which each block possessses and which gives one boundary surface for the polyhedron.

in the autoclave according to FIGURES 5 and 6 the body formed by the blocks is enclosed in a Huid illed cylindrical container consisting of a cylindrical part S1 and two covers 82. The numeral 83 indicates a high pressure chamber which is bounded by an inner tube gd situated within the cylinder sector shaped block 35 and by the covers 82,. The blocks are separated by substantially radially directed interstices, gaps or slots 85. The interstices are sealed against the outer pressure chamber S7 with a thin cylinder shaped shell SS. The pressure chamber 57 is fluid tight against the parts 8l, 82 and 38 with a membrane S? of elastic material, eg. rubber. The chamber 87 communicates through the channel 9? with an outer pressure source not shown, eg. a liquid compressor. The interstices 82 can be iri communication with the outer atmosphere through channels in the covers. The pressure in the chamber S3 is brought about by moving thevblocks S5 inwards. This movement is possible because there are interstices Se between the blocks. The movement is brought about by pumping in a pressure medium to the pressure chamber 87. Thanks to the geometrical form of the blocks a multiplication of the pressure from the chamber 87 to the chamber S3 is obtained. The pressure in the chamber e7 is outwardly absorbed by the cylinder 81 and by the covers 82 which are supported by a press stand not shown in the gures. As examples o' usable materials for integral, critical parts can be mentioned: for the parts 8l and 82, the tool steel RO 7155 (AB Bofors, Sweden) with a hardness of RC 40, for the part 84 the tool steel C 550 (Fagersta Brul; AB, Sweden) or SAE/ AISl A2 with a hardness of RC 55, for the blocks 8S the tool steel C 550 or SAE/AISI A2 with a hardness or RC 6() or a hardmetal such as Coromant H5 (Sandvikens ernverks AB) or Carboloy 999 (General Electric Co.) and for the part 88 a steel with 0.15 percent carbon.

I claim:

l. High pressure apparatus comprising four pressure transmitting blocks movable relative to each other, each block having the form of a truncated spherical sector with a top surface in the form of an equilateral triangle lying in a plane running perpendicular to the symmetry axis of said spherical sector and side surfaces lying in planes running through the sides of said equilateral triangle and through the centre of a sphere of which said spherical sector is a part, said top surfaces of said spherical sectors defining an inner chamber in the form of a regular tetrahedron in which a material is placed to be subjected to high pressure, an outer chamber, said pressure transmitting blocks and said inner chamber being enclosed in said outer chamber, means to supply a pressure mediurn to said outer chamber to exert a pressure on said pressure transmitting locks and to cause a relative movement of said blocks to decrease the volume of said inner chamber, said pressure transmitting blocks being separated from each other by gaps defined by said side surfaces of said pressure transmitting blocks and extending substantially in planes intersecting each other in the centre of said inner chamber, means sealing said gaps from said outer chamber containing said pressure medium to prevent said pressure medium from entering said gaps and means connecting said gaps to a space having a low pressure to keep down the pressure in said gaps and facilitate the movement of said pressure transmitting means.

2. High pressure apparatus comprising six pressure transmitting blocks movable relative to each other, each lock having the form of a truncated spherical sector with a top surface in the form of a square lying in a plane running perpendicular to the axis of symmetry of said spherical sector and side surfaces lying in planes running through the sides of said square and through the centre of a sphere of which said spherical sector is a part, said top surfaces of said spherical sectors detining an inner chamber in the form of a cube in which a material is placed to be subjected to high pressure, an outer chamber, said pressure transmitting blocks and said inner chamber being enclosed in said outer chamber, means to supply a pressure medium to said outer chamber to exert a pressure on said pressure transmitting blocks and to cause a relative movement of said blocks to decrease the volume of said inner chamber, said pressure transmitting blocks being separated from each other by gaps defined by said side surfaces of said pressure transmitting blocks and extending substantially in planes intersecting each other in the centre of said inner chamber, means sealing said gaps from said outer chamber containing said pressure medium to prevent said pressure medium from entering said gaps, means connecting said gaps to a space having a low pressure to keep down the pressure in said gaps and facilitate the movement of said pressure transmitting means 3. High pressure apparatus comprising a plurality of pressure transmitting movable blocks surrounding an inner chamber in which a material is placed to be subjected to high pressure, the cross sectional surfaces of said pressure transmitting blocks decreasing in a direction towards said inner chamber, an outer chamber, said pressure transmitting blocks and said inner chamber being enclosed in said outer chamber, means to introduce a pressure medium into said outer chamber to exert a pressure on said pressure transmitting blocks and to cause a movement of said blocks towards said inner chamber, said pressure transmitting blocks being separated from each other by gaps defined therebetween and extending substantially in planes running through said inner chamber, sealing means tightly sealing said gaps from said outer chamber containing said pressure medium to prevent said pressure medium from entering the gaps, and means connecting said gaps to a space having a low pressure to keep down the pressure in said gaps and facilitate the movement of said pressure transmitting means.

4. High pressure apparatus comprising a plurality of pressure transmitting movable blocks surrounding an inner chamber in which a material is placed to be subjected to high pressure, the cross sectional surfaces of said pressure transmitting blocks decreasing in a direction towards said inner chamber, an outer chamber, said pressure transmitting blocks and said inner chamber being enclosed in said outer chamber to exert a pressure on said pressure transmitting blocks and to cause a movement of said blocks towards said inner chamber, said pressure transmitting blocks being separated from each other by gaps deiined therebetween and extending substantially in planes running through said inner chamber, sealing means tightly sealing said gaps from said outer chamber containing said pressure medium to prevent said pressure medium from entering the gaps, and means connecting said gaps to a cooling medium source to keep down the temperature in said gaps and facilitate the movement of said pressure transmitting means.

5. High pressure apparatus comprising a plurality of ressure transmitting blocks movable relative to each other surrounding an inner chamber in which a material is placed to be subjected to high pressure, the cross sectional surfaces of said pressure transmitting blocks decreasing in a direction towards said inner chamber, an outer chamber, said pressure transmitting blocks and said inner chamber being enclosed in said outer chamber, means to introduce a pressure medium into said outer chamber to exert a pressure on said pressure transmitting blocks and to cause a relative movement of said blocks to decrease the volume of said inner chamber, said pressure transmitting blocks being separated from each other by gaps defined therebetween and extending substantially in planes running through said inner chamber, sealing means tightly sealing said gaps from said outer chamber containing said pressure medium to prevent said pressure medium from entering the gaps, and means connecting said gaps to a space having a low pressure to keep down the pressure in said gaps and facilitate the movement of said pressure transmitting means.

6. High pressure apparatus as claimed in claim 5, in which sealing means are provided to seal said gaps from said inner chamber.

7. High pressure apparatus as claimed in claim 5, in which said blocks consist of a plurality of concentric parts combined with each other mechanically.

8. High pressure apparatus comprisnig a plurality of pressure transmitting blocks movable relative to each other surrounding an inner chamber in which a material is placed to be subjected t0 high pressure, the cross sectional surfaces of said pressure transmitting blocks decreasing in a direction towards said inner chamber, an outer chaxnber, said pressure transmitting blocks and said inner charnber being enclosed in said outer chamber, means to introduce a pressure medium into said outer chamber to exert a pressure on said pressure transmitting blocks and to cause a relative movement of said blocks to decrease the volume of said inner chamber, said pressure transmitting blocks being separated from each other by gaps dened therebetween and extending substantially in planes running through said inner chamber, sealing means tightly sealing said gaps from said outer chamber containing said pressure medium to prevent said pressure medium from entering the gaps, and means connecting said gaps to a cooling medium source to keep down the temperature in said gaps and facilitate the movement of said pressure transmitting means.

9. High pressure apparatus comprising a plurality of pressure transmitting movable blocks surrounding an inner chamber in which a material is placed to be subjected to high pressure, the cross sectional surfaces of said pressure transmitting blocks decreasing in a direction towards said inner chamber, an outer chamber, said pressure tran ittin g blocks and said inner chamber being enclosed in said outer chamber, means to introduce a pressure medium into said outer chamber to exert a pressure on said pressure transmitting blocks and to cause a movement o sa'd biocirs towards said inner chamber, said pressure transmitting blocus being separated from each other by gaps dened therebetween and extending substantially in planes intersecting each other in the middle of said inner chamber, sealing means tiglitiy sealing said gaps from s d outer chamber containing said pressure medium to prevent said pressure medium from entering the gaps, and means connecting said gaps to the atmosphere to keep down the pressure in said `gaps, and facilitate the movement of said pressure transmitting means.

10. High pressure apparatus comprising a plurality of pressure transmitting movable blocks surrounding inner chamber in which a material is placed to be subjected to high pressure, the cross sectional surfaces of said pressure transmitting blocks decreasing in a direction towards said inner chamber, an outer chamber, said pressure transmitting blocks and said inner chamber being enclosed in said outer chamber, means to introduce a pressure medium into said outer chamber, to exert a pressure on said pressure transmitting blocks and to cause a movement of said blocks towards said inner chamber, said pressure transmitting blocks being separated from each other by gaps defined therebetween and extending substantially in planes intersecting eacli other in tbe middle of said inner chamber, sealing means tightly sealing said gaps from said outer chamber containing said pressure medium to prevent said pressure medium from entering the gaps, and means conn ng said gaps to a cooling medium source to keep down the temperature in said gaps and faciiitate the movement of said pressure transmitting means.

References Cited in the tile of this patent UNITED STATES PATENTS 2,745,713 Suits May 15, 1956 2,883,761 Sauer Apr. 28, 1959 2,941,252 Bovenkerk June 2'1, 1960 2,947,034 Vfentorf Aug. 2, 1960 2,958,837 Zeitlin et al ian. 24, 1961 3,044,113 Gerard et al July 17, 1962 

1. HIGH PRESSURE APPARATUS COMPRISING FOUR PRESSURE TRANSMITTING BLOCKS MOVABLE RELATIVE TO EACH OTHER, EACH BLOCK HAVING THE FORM OF A TRUNCATED SPHERICAL SECTOR WITH A TOP SURFACE IN THE FORM OF AN EQUILATERAL TRIANGLE LYING IN A PLANE RUNNING PERPENDICULAR TO THE SYMMETRY AXIS OF SAID SPHERICAL SECTOR AND SIDE SURFACES LYING IN PLANES RUNNING THROUGH THE SIDES OF SAID EQUILATERAL TRIANGLE AND THROUGH THE CENTRE OF A SPHERE OF WHICH SAID SPHERICAL SECTOR IS A PART, SAID TOP SURFACES OF SAID SPHERICAL SECTORS DEFINING AN INNER CHAMBER IN THE FORM OF A REGULAR TETRAHEDRON IN WHICH A MATERIAL IS PLACED TO BE SUBJECTED TO HIGH PRESSURE, AN OUTER CHAMBER, SAID PRESSURE TRANSMITTING BLOCKS AND SAID INNER CHAMBER BEING ENCLOSED IN SAID OUTER CHAMBER, MEANS TO SUPPLY A PRESSURE MEDIUM TO SAID OUTER CHAMBER TO EXERT A PRESSURE ON SAID PRESSURE TRANSMITTING BLOCKS AND TO CAUSE A RELATIVE MOVEMENT OF SAID BLOCKS TO DECREASE THE VOLUME OF SAID INNER CHAMBER, SAID PRESSURE TRANSMITTING BLOCKS BEING SEPARATED FROM EACH OTHER BY GAPS DEFINED BY SAID SIDE SURFACES OF SAID PRESSURE TRANSMITTING BLOCKS AND EXTENDING SUBSTANTIALLY IN PLANES INTERSECTING EACH OTHER IN THE CENTRE OF SAID INNER CHAMBER, MEANS SEALING SAID GAPS FROM SAID OUTER CHAMBER CONTAINING SAID PRESSURE MEDIUM TO PREVENT SAID PRESSURE MEDIUM FROM ENTERING SAID GAPS AND MEANS CONNECTING SAID GAPS TO A SPACE HAVING A LOW PRESSURE TO KEEP DOWN THE PRESSURE IN SAID GAPS AND FACILITATE THE MOVEMENT OF SAID PRESSURE TRANSMITTING MEANS. 